1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: bsdf.c,v 2.10 2011/01/06 04:36:16 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* Routines for handling BSDF data |
6 |
*/ |
7 |
|
8 |
#include "standard.h" |
9 |
#include "bsdf.h" |
10 |
#include "paths.h" |
11 |
#include "ezxml.h" |
12 |
#include <ctype.h> |
13 |
|
14 |
#define MAXLATS 46 /* maximum number of latitudes */ |
15 |
|
16 |
/* BSDF angle specification */ |
17 |
typedef struct { |
18 |
char name[64]; /* basis name */ |
19 |
int nangles; /* total number of directions */ |
20 |
struct { |
21 |
float tmin; /* starting theta */ |
22 |
short nphis; /* number of phis (0 term) */ |
23 |
} lat[MAXLATS+1]; /* latitudes */ |
24 |
} ANGLE_BASIS; |
25 |
|
26 |
#define MAXABASES 7 /* limit on defined bases */ |
27 |
|
28 |
static ANGLE_BASIS abase_list[MAXABASES] = { |
29 |
{ |
30 |
"LBNL/Klems Full", 145, |
31 |
{ {-5., 1}, |
32 |
{5., 8}, |
33 |
{15., 16}, |
34 |
{25., 20}, |
35 |
{35., 24}, |
36 |
{45., 24}, |
37 |
{55., 24}, |
38 |
{65., 16}, |
39 |
{75., 12}, |
40 |
{90., 0} } |
41 |
}, { |
42 |
"LBNL/Klems Half", 73, |
43 |
{ {-6.5, 1}, |
44 |
{6.5, 8}, |
45 |
{19.5, 12}, |
46 |
{32.5, 16}, |
47 |
{46.5, 20}, |
48 |
{61.5, 12}, |
49 |
{76.5, 4}, |
50 |
{90., 0} } |
51 |
}, { |
52 |
"LBNL/Klems Quarter", 41, |
53 |
{ {-9., 1}, |
54 |
{9., 8}, |
55 |
{27., 12}, |
56 |
{46., 12}, |
57 |
{66., 8}, |
58 |
{90., 0} } |
59 |
} |
60 |
}; |
61 |
|
62 |
static int nabases = 3; /* current number of defined bases */ |
63 |
|
64 |
#define FEQ(a,b) ((a)-(b) <= 1e-6 && (b)-(a) <= 1e-6) |
65 |
|
66 |
static int |
67 |
fequal(double a, double b) |
68 |
{ |
69 |
if (b != .0) |
70 |
a = a/b - 1.; |
71 |
return((a <= 1e-6) & (a >= -1e-6)); |
72 |
} |
73 |
|
74 |
// returns the name of the given tag |
75 |
#ifdef ezxml_name |
76 |
#undef ezxml_name |
77 |
static char * |
78 |
ezxml_name(ezxml_t xml) |
79 |
{ |
80 |
if (xml == NULL) |
81 |
return(NULL); |
82 |
return(xml->name); |
83 |
} |
84 |
#endif |
85 |
|
86 |
// returns the given tag's character content or empty string if none |
87 |
#ifdef ezxml_txt |
88 |
#undef ezxml_txt |
89 |
static char * |
90 |
ezxml_txt(ezxml_t xml) |
91 |
{ |
92 |
if (xml == NULL) |
93 |
return(""); |
94 |
return(xml->txt); |
95 |
} |
96 |
#endif |
97 |
|
98 |
|
99 |
static int |
100 |
ab_getvec( /* get vector for this angle basis index */ |
101 |
FVECT v, |
102 |
int ndx, |
103 |
void *p |
104 |
) |
105 |
{ |
106 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
107 |
int li; |
108 |
double pol, azi, d; |
109 |
|
110 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
111 |
return(0); |
112 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
113 |
ndx -= ab->lat[li].nphis; |
114 |
pol = PI/180.*0.5*(ab->lat[li].tmin + ab->lat[li+1].tmin); |
115 |
azi = 2.*PI*ndx/ab->lat[li].nphis; |
116 |
v[2] = d = cos(pol); |
117 |
d = sqrt(1. - d*d); /* sin(pol) */ |
118 |
v[0] = cos(azi)*d; |
119 |
v[1] = sin(azi)*d; |
120 |
return(1); |
121 |
} |
122 |
|
123 |
|
124 |
static int |
125 |
ab_getndx( /* get index corresponding to the given vector */ |
126 |
FVECT v, |
127 |
void *p |
128 |
) |
129 |
{ |
130 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
131 |
int li, ndx; |
132 |
double pol, azi, d; |
133 |
|
134 |
if ((v[2] < -1.0) | (v[2] > 1.0)) |
135 |
return(-1); |
136 |
pol = 180.0/PI*acos(v[2]); |
137 |
azi = 180.0/PI*atan2(v[1], v[0]); |
138 |
if (azi < 0.0) azi += 360.0; |
139 |
for (li = 1; ab->lat[li].tmin <= pol; li++) |
140 |
if (!ab->lat[li].nphis) |
141 |
return(-1); |
142 |
--li; |
143 |
ndx = (int)((1./360.)*azi*ab->lat[li].nphis + 0.5); |
144 |
if (ndx >= ab->lat[li].nphis) ndx = 0; |
145 |
while (li--) |
146 |
ndx += ab->lat[li].nphis; |
147 |
return(ndx); |
148 |
} |
149 |
|
150 |
|
151 |
static double |
152 |
ab_getohm( /* get solid angle for this angle basis index */ |
153 |
int ndx, |
154 |
void *p |
155 |
) |
156 |
{ |
157 |
ANGLE_BASIS *ab = (ANGLE_BASIS *)p; |
158 |
int li; |
159 |
double theta, theta1; |
160 |
|
161 |
if ((ndx < 0) | (ndx >= ab->nangles)) |
162 |
return(0); |
163 |
for (li = 0; ndx >= ab->lat[li].nphis; li++) |
164 |
ndx -= ab->lat[li].nphis; |
165 |
theta1 = PI/180. * ab->lat[li+1].tmin; |
166 |
if (ab->lat[li].nphis == 1) { /* special case */ |
167 |
if (ab->lat[li].tmin > FTINY) |
168 |
error(USER, "unsupported BSDF coordinate system"); |
169 |
return(2.*PI*(1. - cos(theta1))); |
170 |
} |
171 |
theta = PI/180. * ab->lat[li].tmin; |
172 |
return(2.*PI*(cos(theta) - cos(theta1))/(double)ab->lat[li].nphis); |
173 |
} |
174 |
|
175 |
|
176 |
static int |
177 |
ab_getvecR( /* get reverse vector for this angle basis index */ |
178 |
FVECT v, |
179 |
int ndx, |
180 |
void *p |
181 |
) |
182 |
{ |
183 |
if (!ab_getvec(v, ndx, p)) |
184 |
return(0); |
185 |
|
186 |
v[0] = -v[0]; |
187 |
v[1] = -v[1]; |
188 |
v[2] = -v[2]; |
189 |
|
190 |
return(1); |
191 |
} |
192 |
|
193 |
|
194 |
static int |
195 |
ab_getndxR( /* get index corresponding to the reverse vector */ |
196 |
FVECT v, |
197 |
void *p |
198 |
) |
199 |
{ |
200 |
FVECT v2; |
201 |
|
202 |
v2[0] = -v[0]; |
203 |
v2[1] = -v[1]; |
204 |
v2[2] = -v[2]; |
205 |
|
206 |
return ab_getndx(v2, p); |
207 |
} |
208 |
|
209 |
|
210 |
static void |
211 |
load_angle_basis( /* load custom BSDF angle basis */ |
212 |
ezxml_t wab |
213 |
) |
214 |
{ |
215 |
char *abname = ezxml_txt(ezxml_child(wab, "AngleBasisName")); |
216 |
ezxml_t wbb; |
217 |
int i; |
218 |
|
219 |
if (!abname || !*abname) |
220 |
return; |
221 |
for (i = nabases; i--; ) |
222 |
if (!strcasecamp(abname, abase_list[i].name)) |
223 |
return; /* assume it's the same */ |
224 |
if (nabases >= MAXABASES) |
225 |
error(INTERNAL, "too many angle bases"); |
226 |
strcpy(abase_list[nabases].name, abname); |
227 |
abase_list[nabases].nangles = 0; |
228 |
for (i = 0, wbb = ezxml_child(wab, "AngleBasisBlock"); |
229 |
wbb != NULL; i++, wbb = wbb->next) { |
230 |
if (i >= MAXLATS) |
231 |
error(INTERNAL, "too many latitudes in custom basis"); |
232 |
abase_list[nabases].lat[i+1].tmin = atof(ezxml_txt( |
233 |
ezxml_child(ezxml_child(wbb, |
234 |
"ThetaBounds"), "UpperTheta"))); |
235 |
if (!i) |
236 |
abase_list[nabases].lat[i].tmin = |
237 |
-abase_list[nabases].lat[i+1].tmin; |
238 |
else if (!fequal(atof(ezxml_txt(ezxml_child(ezxml_child(wbb, |
239 |
"ThetaBounds"), "LowerTheta"))), |
240 |
abase_list[nabases].lat[i].tmin)) |
241 |
error(WARNING, "theta values disagree in custom basis"); |
242 |
abase_list[nabases].nangles += |
243 |
abase_list[nabases].lat[i].nphis = |
244 |
atoi(ezxml_txt(ezxml_child(wbb, "nPhis"))); |
245 |
} |
246 |
abase_list[nabases++].lat[i].nphis = 0; |
247 |
} |
248 |
|
249 |
|
250 |
static double |
251 |
to_meters( /* return factor to convert given unit to meters */ |
252 |
const char *unit |
253 |
) |
254 |
{ |
255 |
if (unit == NULL) return(1.); /* safe assumption? */ |
256 |
if (!strcasecmp(unit, "Meter")) return(1.); |
257 |
if (!strcasecmp(unit, "Foot")) return(.3048); |
258 |
if (!strcasecmp(unit, "Inch")) return(.0254); |
259 |
if (!strcasecmp(unit, "Centimeter")) return(.01); |
260 |
if (!strcasecmp(unit, "Millimeter")) return(.001); |
261 |
sprintf(errmsg, "unknown dimensional unit '%s'", unit); |
262 |
error(USER, errmsg); |
263 |
} |
264 |
|
265 |
|
266 |
static void |
267 |
load_geometry( /* load geometric dimensions and description (if any) */ |
268 |
struct BSDF_data *dp, |
269 |
ezxml_t wdb |
270 |
) |
271 |
{ |
272 |
ezxml_t geom; |
273 |
double cfact; |
274 |
const char *fmt, *mgfstr; |
275 |
|
276 |
dp->dim[0] = dp->dim[1] = dp->dim[2] = 0; |
277 |
dp->mgf = NULL; |
278 |
if ((geom = ezxml_child(wdb, "Width")) != NULL) |
279 |
dp->dim[0] = atof(ezxml_txt(geom)) * |
280 |
to_meters(ezxml_attr(geom, "unit")); |
281 |
if ((geom = ezxml_child(wdb, "Height")) != NULL) |
282 |
dp->dim[1] = atof(ezxml_txt(geom)) * |
283 |
to_meters(ezxml_attr(geom, "unit")); |
284 |
if ((geom = ezxml_child(wdb, "Thickness")) != NULL) |
285 |
dp->dim[2] = atof(ezxml_txt(geom)) * |
286 |
to_meters(ezxml_attr(geom, "unit")); |
287 |
if ((geom = ezxml_child(wdb, "Geometry")) == NULL || |
288 |
(mgfstr = ezxml_txt(geom)) == NULL) |
289 |
return; |
290 |
if ((fmt = ezxml_attr(geom, "format")) != NULL && |
291 |
strcasecmp(fmt, "MGF")) { |
292 |
sprintf(errmsg, "unrecognized geometry format '%s'", fmt); |
293 |
error(WARNING, errmsg); |
294 |
return; |
295 |
} |
296 |
cfact = to_meters(ezxml_attr(geom, "unit")); |
297 |
dp->mgf = (char *)malloc(strlen(mgfstr)+32); |
298 |
if (dp->mgf == NULL) |
299 |
error(SYSTEM, "out of memory in load_geometry"); |
300 |
if (cfact < 0.99 || cfact > 1.01) |
301 |
sprintf(dp->mgf, "xf -s %.5f\n%s\nxf\n", cfact, mgfstr); |
302 |
else |
303 |
strcpy(dp->mgf, mgfstr); |
304 |
} |
305 |
|
306 |
|
307 |
static void |
308 |
load_bsdf_data( /* load BSDF distribution for this wavelength */ |
309 |
struct BSDF_data *dp, |
310 |
ezxml_t wdb |
311 |
) |
312 |
{ |
313 |
char *cbasis = ezxml_txt(ezxml_child(wdb,"ColumnAngleBasis")); |
314 |
char *rbasis = ezxml_txt(ezxml_child(wdb,"RowAngleBasis")); |
315 |
char *sdata; |
316 |
int i; |
317 |
|
318 |
if ((!cbasis || !*cbasis) | (!rbasis || !*rbasis)) { |
319 |
error(WARNING, "missing column/row basis for BSDF"); |
320 |
return; |
321 |
} |
322 |
for (i = nabases; i--; ) |
323 |
if (!strcasecamp(cbasis, abase_list[i].name)) { |
324 |
dp->ninc = abase_list[i].nangles; |
325 |
dp->ib_priv = (void *)&abase_list[i]; |
326 |
dp->ib_vec = ab_getvecR; |
327 |
dp->ib_ndx = ab_getndxR; |
328 |
dp->ib_ohm = ab_getohm; |
329 |
break; |
330 |
} |
331 |
if (i < 0) { |
332 |
sprintf(errmsg, "undefined ColumnAngleBasis '%s'", cbasis); |
333 |
error(WARNING, errmsg); |
334 |
return; |
335 |
} |
336 |
for (i = nabases; i--; ) |
337 |
if (!strcasecamp(rbasis, abase_list[i].name)) { |
338 |
dp->nout = abase_list[i].nangles; |
339 |
dp->ob_priv = (void *)&abase_list[i]; |
340 |
dp->ob_vec = ab_getvec; |
341 |
dp->ob_ndx = ab_getndx; |
342 |
dp->ob_ohm = ab_getohm; |
343 |
break; |
344 |
} |
345 |
if (i < 0) { |
346 |
sprintf(errmsg, "undefined RowAngleBasis '%s'", cbasis); |
347 |
error(WARNING, errmsg); |
348 |
return; |
349 |
} |
350 |
/* read BSDF data */ |
351 |
sdata = ezxml_txt(ezxml_child(wdb,"ScatteringData")); |
352 |
if (!sdata || !*sdata) { |
353 |
error(WARNING, "missing BSDF ScatteringData"); |
354 |
return; |
355 |
} |
356 |
dp->bsdf = (float *)malloc(sizeof(float)*dp->ninc*dp->nout); |
357 |
if (dp->bsdf == NULL) |
358 |
error(SYSTEM, "out of memory in load_bsdf_data"); |
359 |
for (i = 0; i < dp->ninc*dp->nout; i++) { |
360 |
char *sdnext = fskip(sdata); |
361 |
if (sdnext == NULL) { |
362 |
error(WARNING, "bad/missing BSDF ScatteringData"); |
363 |
free(dp->bsdf); dp->bsdf = NULL; |
364 |
return; |
365 |
} |
366 |
while (*sdnext && isspace(*sdnext)) |
367 |
sdnext++; |
368 |
if (*sdnext == ',') sdnext++; |
369 |
dp->bsdf[i] = atof(sdata); |
370 |
sdata = sdnext; |
371 |
} |
372 |
while (isspace(*sdata)) |
373 |
sdata++; |
374 |
if (*sdata) { |
375 |
sprintf(errmsg, "%d extra characters after BSDF ScatteringData", |
376 |
(int)strlen(sdata)); |
377 |
error(WARNING, errmsg); |
378 |
} |
379 |
} |
380 |
|
381 |
|
382 |
static int |
383 |
check_bsdf_data( /* check that BSDF data is sane */ |
384 |
struct BSDF_data *dp |
385 |
) |
386 |
{ |
387 |
double *omega_iarr, *omega_oarr; |
388 |
double dom, contrib, hemi_total, full_total; |
389 |
int nneg; |
390 |
FVECT v; |
391 |
int i, o; |
392 |
|
393 |
if (dp == NULL || dp->bsdf == NULL) |
394 |
return(0); |
395 |
omega_iarr = (double *)calloc(dp->ninc, sizeof(double)); |
396 |
omega_oarr = (double *)calloc(dp->nout, sizeof(double)); |
397 |
if ((omega_iarr == NULL) | (omega_oarr == NULL)) |
398 |
error(SYSTEM, "out of memory in check_bsdf_data"); |
399 |
/* incoming projected solid angles */ |
400 |
hemi_total = .0; |
401 |
for (i = dp->ninc; i--; ) { |
402 |
dom = getBSDF_incohm(dp,i); |
403 |
if (dom <= .0) { |
404 |
error(WARNING, "zero/negative incoming solid angle"); |
405 |
continue; |
406 |
} |
407 |
if (!getBSDF_incvec(v,dp,i) || v[2] > FTINY) { |
408 |
error(WARNING, "illegal incoming BSDF direction"); |
409 |
free(omega_iarr); free(omega_oarr); |
410 |
return(0); |
411 |
} |
412 |
hemi_total += omega_iarr[i] = dom * -v[2]; |
413 |
} |
414 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
415 |
sprintf(errmsg, "incoming BSDF hemisphere off by %.1f%%", |
416 |
100.*(hemi_total/PI - 1.)); |
417 |
error(WARNING, errmsg); |
418 |
} |
419 |
dom = PI / hemi_total; /* fix normalization */ |
420 |
for (i = dp->ninc; i--; ) |
421 |
omega_iarr[i] *= dom; |
422 |
/* outgoing projected solid angles */ |
423 |
hemi_total = .0; |
424 |
for (o = dp->nout; o--; ) { |
425 |
dom = getBSDF_outohm(dp,o); |
426 |
if (dom <= .0) { |
427 |
error(WARNING, "zero/negative outgoing solid angle"); |
428 |
continue; |
429 |
} |
430 |
if (!getBSDF_outvec(v,dp,o) || v[2] < -FTINY) { |
431 |
error(WARNING, "illegal outgoing BSDF direction"); |
432 |
free(omega_iarr); free(omega_oarr); |
433 |
return(0); |
434 |
} |
435 |
hemi_total += omega_oarr[o] = dom * v[2]; |
436 |
} |
437 |
if ((hemi_total > 1.02*PI) | (hemi_total < 0.98*PI)) { |
438 |
sprintf(errmsg, "outgoing BSDF hemisphere off by %.1f%%", |
439 |
100.*(hemi_total/PI - 1.)); |
440 |
error(WARNING, errmsg); |
441 |
} |
442 |
dom = PI / hemi_total; /* fix normalization */ |
443 |
for (o = dp->nout; o--; ) |
444 |
omega_oarr[o] *= dom; |
445 |
nneg = 0; /* check outgoing totals */ |
446 |
for (i = 0; i < dp->ninc; i++) { |
447 |
hemi_total = .0; |
448 |
for (o = dp->nout; o--; ) { |
449 |
double f = BSDF_value(dp,i,o); |
450 |
if (f >= .0) |
451 |
hemi_total += f*omega_oarr[o]; |
452 |
else { |
453 |
nneg += (f < -FTINY); |
454 |
BSDF_value(dp,i,o) = .0f; |
455 |
} |
456 |
} |
457 |
if (hemi_total > 1.01) { |
458 |
sprintf(errmsg, |
459 |
"incoming BSDF direction %d passes %.1f%% of light", |
460 |
i, 100.*hemi_total); |
461 |
error(WARNING, errmsg); |
462 |
} |
463 |
} |
464 |
if (nneg) { |
465 |
sprintf(errmsg, "%d negative BSDF values (ignored)", nneg); |
466 |
error(WARNING, errmsg); |
467 |
} |
468 |
full_total = .0; /* reverse roles and check again */ |
469 |
for (o = 0; o < dp->nout; o++) { |
470 |
hemi_total = .0; |
471 |
for (i = dp->ninc; i--; ) |
472 |
hemi_total += BSDF_value(dp,i,o) * omega_iarr[i]; |
473 |
|
474 |
if (hemi_total > 1.01) { |
475 |
sprintf(errmsg, |
476 |
"outgoing BSDF direction %d collects %.1f%% of light", |
477 |
o, 100.*hemi_total); |
478 |
error(WARNING, errmsg); |
479 |
} |
480 |
full_total += hemi_total*omega_oarr[o]; |
481 |
} |
482 |
full_total /= PI; |
483 |
if (full_total > 1.00001) { |
484 |
sprintf(errmsg, "BSDF transfers %.4f%% of light", |
485 |
100.*full_total); |
486 |
error(WARNING, errmsg); |
487 |
} |
488 |
free(omega_iarr); free(omega_oarr); |
489 |
return(1); |
490 |
} |
491 |
|
492 |
|
493 |
struct BSDF_data * |
494 |
load_BSDF( /* load BSDF data from file */ |
495 |
char *fname |
496 |
) |
497 |
{ |
498 |
char *path; |
499 |
ezxml_t fl, wtl, wld, wdb; |
500 |
struct BSDF_data *dp; |
501 |
|
502 |
path = getpath(fname, getrlibpath(), R_OK); |
503 |
if (path == NULL) { |
504 |
sprintf(errmsg, "cannot find BSDF file \"%s\"", fname); |
505 |
error(WARNING, errmsg); |
506 |
return(NULL); |
507 |
} |
508 |
fl = ezxml_parse_file(path); |
509 |
if (fl == NULL) { |
510 |
sprintf(errmsg, "cannot open BSDF \"%s\"", path); |
511 |
error(WARNING, errmsg); |
512 |
return(NULL); |
513 |
} |
514 |
if (ezxml_error(fl)[0]) { |
515 |
sprintf(errmsg, "BSDF \"%s\" %s", path, ezxml_error(fl)); |
516 |
error(WARNING, errmsg); |
517 |
ezxml_free(fl); |
518 |
return(NULL); |
519 |
} |
520 |
if (strcmp(ezxml_name(fl), "WindowElement")) { |
521 |
sprintf(errmsg, |
522 |
"BSDF \"%s\": top level node not 'WindowElement'", |
523 |
path); |
524 |
error(WARNING, errmsg); |
525 |
ezxml_free(fl); |
526 |
return(NULL); |
527 |
} |
528 |
wtl = ezxml_child(ezxml_child(fl, "Optical"), "Layer"); |
529 |
if (strcasecmp(ezxml_txt(ezxml_child(ezxml_child(wtl, |
530 |
"DataDefinition"), "IncidentDataStructure")), |
531 |
"Columns")) { |
532 |
sprintf(errmsg, |
533 |
"BSDF \"%s\": unsupported IncidentDataStructure", |
534 |
path); |
535 |
error(WARNING, errmsg); |
536 |
ezxml_free(fl); |
537 |
return(NULL); |
538 |
} |
539 |
load_angle_basis(ezxml_child(ezxml_child(wtl, |
540 |
"DataDefinition"), "AngleBasis")); |
541 |
dp = (struct BSDF_data *)calloc(1, sizeof(struct BSDF_data)); |
542 |
load_geometry(dp, ezxml_child(wtl, "Material")); |
543 |
for (wld = ezxml_child(wtl, "WavelengthData"); |
544 |
wld != NULL; wld = wld->next) { |
545 |
if (strcasecamp(ezxml_txt(ezxml_child(wld,"Wavelength")), "Visible")) |
546 |
continue; |
547 |
wdb = ezxml_child(wld, "WavelengthDataBlock"); |
548 |
if (wdb == NULL) continue; |
549 |
if (strcasecamp(ezxml_txt(ezxml_child(wdb,"WavelengthDataDirection")), |
550 |
"Transmission Front")) |
551 |
continue; |
552 |
load_bsdf_data(dp, wdb); /* load front BTDF */ |
553 |
break; /* ignore the rest */ |
554 |
} |
555 |
ezxml_free(fl); /* done with XML file */ |
556 |
if (!check_bsdf_data(dp)) { |
557 |
sprintf(errmsg, "bad/missing BTDF data in \"%s\"", path); |
558 |
error(WARNING, errmsg); |
559 |
free_BSDF(dp); |
560 |
dp = NULL; |
561 |
} |
562 |
return(dp); |
563 |
} |
564 |
|
565 |
|
566 |
void |
567 |
free_BSDF( /* free BSDF data structure */ |
568 |
struct BSDF_data *b |
569 |
) |
570 |
{ |
571 |
if (b == NULL) |
572 |
return; |
573 |
if (b->mgf != NULL) |
574 |
free(b->mgf); |
575 |
if (b->bsdf != NULL) |
576 |
free(b->bsdf); |
577 |
free(b); |
578 |
} |
579 |
|
580 |
|
581 |
int |
582 |
r_BSDF_incvec( /* compute random input vector at given location */ |
583 |
FVECT v, |
584 |
struct BSDF_data *b, |
585 |
int i, |
586 |
double rv, |
587 |
MAT4 xm |
588 |
) |
589 |
{ |
590 |
FVECT pert; |
591 |
double rad; |
592 |
int j; |
593 |
|
594 |
if (!getBSDF_incvec(v, b, i)) |
595 |
return(0); |
596 |
rad = sqrt(getBSDF_incohm(b, i) / PI); |
597 |
multisamp(pert, 3, rv); |
598 |
for (j = 0; j < 3; j++) |
599 |
v[j] += rad*(2.*pert[j] - 1.); |
600 |
if (xm != NULL) |
601 |
multv3(v, v, xm); |
602 |
return(normalize(v) != 0.0); |
603 |
} |
604 |
|
605 |
|
606 |
int |
607 |
r_BSDF_outvec( /* compute random output vector at given location */ |
608 |
FVECT v, |
609 |
struct BSDF_data *b, |
610 |
int o, |
611 |
double rv, |
612 |
MAT4 xm |
613 |
) |
614 |
{ |
615 |
FVECT pert; |
616 |
double rad; |
617 |
int j; |
618 |
|
619 |
if (!getBSDF_outvec(v, b, o)) |
620 |
return(0); |
621 |
rad = sqrt(getBSDF_outohm(b, o) / PI); |
622 |
multisamp(pert, 3, rv); |
623 |
for (j = 0; j < 3; j++) |
624 |
v[j] += rad*(2.*pert[j] - 1.); |
625 |
if (xm != NULL) |
626 |
multv3(v, v, xm); |
627 |
return(normalize(v) != 0.0); |
628 |
} |
629 |
|
630 |
|
631 |
static int |
632 |
addrot( /* compute rotation (x,y,z) => (xp,yp,zp) */ |
633 |
char *xfarg[], |
634 |
FVECT xp, |
635 |
FVECT yp, |
636 |
FVECT zp |
637 |
) |
638 |
{ |
639 |
static char bufs[3][16]; |
640 |
int bn = 0; |
641 |
char **xfp = xfarg; |
642 |
double theta; |
643 |
|
644 |
if (yp[2]*yp[2] + zp[2]*zp[2] < 2.*FTINY*FTINY) { |
645 |
/* Special case for X' along Z-axis */ |
646 |
theta = -atan2(yp[0], yp[1]); |
647 |
*xfp++ = "-ry"; |
648 |
*xfp++ = xp[2] < 0.0 ? "90" : "-90"; |
649 |
*xfp++ = "-rz"; |
650 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
651 |
*xfp++ = bufs[bn++]; |
652 |
return(xfp - xfarg); |
653 |
} |
654 |
theta = atan2(yp[2], zp[2]); |
655 |
if (!FEQ(theta,0.0)) { |
656 |
*xfp++ = "-rx"; |
657 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
658 |
*xfp++ = bufs[bn++]; |
659 |
} |
660 |
theta = asin(-xp[2]); |
661 |
if (!FEQ(theta,0.0)) { |
662 |
*xfp++ = "-ry"; |
663 |
sprintf(bufs[bn], " %f", theta*(180./PI)); |
664 |
*xfp++ = bufs[bn++]; |
665 |
} |
666 |
theta = atan2(xp[1], xp[0]); |
667 |
if (!FEQ(theta,0.0)) { |
668 |
*xfp++ = "-rz"; |
669 |
sprintf(bufs[bn], "%f", theta*(180./PI)); |
670 |
*xfp++ = bufs[bn++]; |
671 |
} |
672 |
*xfp = NULL; |
673 |
return(xfp - xfarg); |
674 |
} |
675 |
|
676 |
|
677 |
int |
678 |
getBSDF_xfm( /* compute BSDF orient. -> world orient. transform */ |
679 |
MAT4 xm, |
680 |
FVECT nrm, |
681 |
UpDir ud, |
682 |
char *xfbuf |
683 |
) |
684 |
{ |
685 |
char *xfargs[7]; |
686 |
XF myxf; |
687 |
FVECT updir, xdest, ydest; |
688 |
int i; |
689 |
|
690 |
updir[0] = updir[1] = updir[2] = 0.; |
691 |
switch (ud) { |
692 |
case UDzneg: |
693 |
updir[2] = -1.; |
694 |
break; |
695 |
case UDyneg: |
696 |
updir[1] = -1.; |
697 |
break; |
698 |
case UDxneg: |
699 |
updir[0] = -1.; |
700 |
break; |
701 |
case UDxpos: |
702 |
updir[0] = 1.; |
703 |
break; |
704 |
case UDypos: |
705 |
updir[1] = 1.; |
706 |
break; |
707 |
case UDzpos: |
708 |
updir[2] = 1.; |
709 |
break; |
710 |
case UDunknown: |
711 |
return(0); |
712 |
} |
713 |
fcross(xdest, updir, nrm); |
714 |
if (normalize(xdest) == 0.0) |
715 |
return(0); |
716 |
fcross(ydest, nrm, xdest); |
717 |
xf(&myxf, addrot(xfargs, xdest, ydest, nrm), xfargs); |
718 |
copymat4(xm, myxf.xfm); |
719 |
if (xfbuf == NULL) |
720 |
return(1); |
721 |
/* return xf arguments as well */ |
722 |
for (i = 0; xfargs[i] != NULL; i++) { |
723 |
*xfbuf++ = ' '; |
724 |
strcpy(xfbuf, xfargs[i]); |
725 |
while (*xfbuf) ++xfbuf; |
726 |
} |
727 |
return(1); |
728 |
} |